According to the story, the ethylene oxide catalyst unit of the facility leaked more than 3,500 total pounds of the gas between February 4 and 16 before Freddie Sizemore, a Dow employee, reported the incident to Kanawha County Metro 911.

Ammonia is a toxic irritant that, depending on exposure levels, can cause severe pulmonary and gastrointestinal irritation, nausea, vomiting and even death, the story stated.

Officials at the facility declined to comment and deferred to the Dow Chemical headquarters in Midland, Michigan, where Dow spokesperson Randy Fischback said there was little to add to what was already reported, the story noted.

Fischback said: "An incident review will be conducted, but our priority has been stopping the release."

Kanawha County Commission President Kent Carper expressed concern over the leak, particularly because of the long lag time between its occurrence and the reporting and resolution of the problem, the story added.